全文获取类型
收费全文 | 669篇 |
免费 | 54篇 |
国内免费 | 22篇 |
专业分类
耳鼻咽喉 | 1篇 |
儿科学 | 36篇 |
妇产科学 | 1篇 |
基础医学 | 66篇 |
口腔科学 | 9篇 |
临床医学 | 116篇 |
内科学 | 150篇 |
皮肤病学 | 10篇 |
神经病学 | 5篇 |
特种医学 | 123篇 |
外科学 | 30篇 |
综合类 | 29篇 |
预防医学 | 18篇 |
眼科学 | 28篇 |
药学 | 36篇 |
肿瘤学 | 87篇 |
出版年
2024年 | 1篇 |
2023年 | 1篇 |
2022年 | 1篇 |
2021年 | 7篇 |
2020年 | 1篇 |
2019年 | 6篇 |
2018年 | 9篇 |
2017年 | 6篇 |
2016年 | 6篇 |
2015年 | 14篇 |
2014年 | 27篇 |
2013年 | 18篇 |
2012年 | 24篇 |
2011年 | 30篇 |
2010年 | 13篇 |
2009年 | 24篇 |
2008年 | 37篇 |
2007年 | 37篇 |
2006年 | 45篇 |
2005年 | 29篇 |
2004年 | 34篇 |
2003年 | 33篇 |
2002年 | 25篇 |
2001年 | 30篇 |
2000年 | 17篇 |
1999年 | 11篇 |
1998年 | 33篇 |
1997年 | 22篇 |
1996年 | 27篇 |
1995年 | 23篇 |
1994年 | 19篇 |
1993年 | 22篇 |
1992年 | 8篇 |
1991年 | 4篇 |
1990年 | 9篇 |
1989年 | 5篇 |
1988年 | 7篇 |
1987年 | 4篇 |
1986年 | 11篇 |
1985年 | 8篇 |
1984年 | 7篇 |
1983年 | 6篇 |
1982年 | 7篇 |
1981年 | 7篇 |
1980年 | 13篇 |
1979年 | 3篇 |
1978年 | 4篇 |
1977年 | 4篇 |
1976年 | 4篇 |
1975年 | 2篇 |
排序方式: 共有745条查询结果,搜索用时 15 毫秒
11.
Mucormycosis is a devastating disease and can occur in patients with a variety of risk factors, the most important of which are immunosuppression, anatomic barrier breakdown, iron overload, and hyperglycemia/acidosis. Similarly to what occurs with Aspergillus, the host stimulates an innate immune response against the challenging sporangiospores and invading hyphae of Zygomycetes. This article discusses the host defense to different Zygomycetes, its augmentation, and its subsequent impact on the outcome of mucormycosis. 相似文献
12.
13.
van Kammen DP McAllister-Sistilli CG Kelley ME Gurklis JA Yao JK 《Psychiatry research》1999,87(2-3):129-136
Interleukin 6 (IL-6) levels have been shown to be increased in a number of autoimmune disorders and have recently been shown to be elevated in the serum of schizophrenic patients. Given the involvement of the CNS in schizophrenia, levels of interleukin-6 in the CSF are also of interest. Thus, we examined levels of both CSF and serum IL-6 concomitantly to determine if these levels were different from control values. In addition, we examined these measures in patients both on and off antipsychotic drugs to determine if any medication or exacerbation effects may account for the difference from controls. CSF IL-6 was measured by ELISA in 61 drug-free male schizophrenic (DSM-IIIR) patients and 25 well-screened healthy male control subjects. Serum IL-6 was measured in 43 of the 61 patients, and in 16 control subjects. Serum IL-6 was significantly higher in the schizophrenic patients compared to control subjects. CSF IL-6 was also higher in the patients, but the difference was not statistically significant. Paired data showed no medication or exacerbation effects on CSF IL-6, but plasma IL-6 significantly decreased in patients that experienced an exacerbation after medication withdrawal. The results indicate that IL-6 levels may be altered in schizophrenia. The relative decrease in exacerbated patients following haloperidol withdrawal may be indicative of a compensatory response of plasma IL-6 levels to relapse. 相似文献
14.
Frequency and species distribution of gliotoxin-producing Aspergillus isolates recovered from patients at a tertiary-care cancer center 总被引:2,自引:0,他引:2
Lewis RE Wiederhold NP Lionakis MS Prince RA Kontoyiannis DP 《Journal of clinical microbiology》2005,43(12):6120-6122
Aspergillus isolates (n = 103) collected from cancer patients were screened to determine the taxonomic distribution and quantity of gliotoxin production. Gliotoxin was detected in 93% of Aspergillus fumigatus, 75% of A. niger, 25% of A. terreus, and 4% of A. flavus cultures. Gliotoxin concentrations were highest in cultures of A. fumigatus. 相似文献
15.
M. S. Lionakis G. P. Bodey J. J. Tarrand I. I. Raad D. P. Kontoyiannis 《Clinical microbiology and infection》2004,10(10):922-925
The significance of blood cultures positive for emerging saprophytic moulds (e.g., Scedosporium apiospermum, Scedosporium prolificans, Paecilomyces spp.) was evaluated in 30 cancer patients (1996-2002). Diagnostic criteria proposed previously for evaluation of aspergillaemia were used. Blood cultures positive for emerging saprophytic moulds represented 1% of all positive fungal cultures. One case of catheter-related fungaemia was excluded. The remaining 29 cases consisted of true (n = 5), probable (n = 1), indeterminate (n = 7) fungaemia, and contamination (n = 16). True fungaemia was seen only in leukaemia patients and allogeneic bone marrow transplant recipients. S. apiospermum and S. prolificans were the commonest causes of true fungaemia. 相似文献
16.
Moore AD; Godwin JD; Muller NL; Naidich DP; Hammar SP; Buschman DL; Takasugi JE; de Carvalho CR 《Radiology》1989,172(1):249-254
The authors retrospectively evaluated radiographs, computed tomographic (CT) scans, and results of pulmonary function tests (when available) for 17 patients with biopsy-proved pulmonary histiocytosis X. In 11 patients, high-resolution CT was used. In 12 patients, CT demonstrated cystic air spaces, usually less than 10 mm in diameter. In three of these 12, cysts were the only abnormality, but in six others, nodules (usually less than 5 mm in diameter) were also present. Two patients had only nodules and one, only emphysema. CT showed that many lesions that appeared reticular on plain radiographs were actually cysts. CT showed no central or peripheral concentration of lesions, but it did reveal that many small nodules were distributed in the centers of secondary lobules around small airways. CT findings correlated better with the diffusing capacity (rho = -0.71) than did the plain radiographic findings (rho = -0.57). Thus, CT was better than radiography at showing the morphology and distribution of lung abnormalities. 相似文献
17.
A A Pontual DP de Melo SM de Almeida FN Bóscolo F Haiter Neto 《Dento maxillo facial radiology》2010,39(7):431-436
Objectives
The aims of this study were (1) to compare the accuracy of the detection of approximal enamel caries lesions using three intraoral storage phosphor plate digital systems and one conventional film-based radiographic system; and (2) to determine whether there is a correlation between the histological and radiographic measurements of enamel caries.Methods
160 approximal surfaces were radiographed under standardized conditions using three storage phosphor stimulable systems (DenOptix and Digora FMX with white and blue plates), and one film system (Insight film). 17 observers scored the images for the presence and depth of caries using a 4-point scale. The presence of caries was validated histologically (gold standard). Two-way analysis of variance was used to test the differences in sensitivity, specificity and overall accuracy (TP + TN). The data from the radiographic and histological measurements were statistically analysed by Spearman’s rank correlation coefficient.Results
Two-way analysis of variance and the post hoc t-test demonstrated that Digora (white plate) had higher specificity and overall accuracy values than DenOptix (P = 0.021); there was no statistically significant difference among the other imaging modalities (P > 0.05). There was no significant correlation between the histological depth measurements and the radiographic measurements from Digora (blue plate) (P = 0.43), Digora (white plate) (P = 0.15), DenOptix (P = 0.17) and Insight film (P = 0.06).Conclusions
The results suggest that (1) the performance of the three storage phosphor image plate systems was similar to that of the Insight film for detection of approximal enamel caries, and (2) the increase in histological depth of enamel caries was not significantly correlated with radiographic measurements. 相似文献18.
The vascularity of 49 renal masses (26 malignant and 23 benign lesions) was investigated with duplex Doppler ultrasound. Doppler signals obtained at the margins of renal masses were defined as "tumor signals" when the Doppler-shifted frequency of the lesion exceeded the frequency shift in the ipsilateral main renal artery. These exceeded 2.5 kHz with a 3-MHz insonating frequency. Among the 26 renal masses that subsequently proved to be malignant, tumor signals were obtained in 15 of 18 (83%) untreated renal cell carcinomas, in three of four Wilms tumors, and in two patients with metastases to the kidney, but not in the one patient with lymphoma. None of the 23 benign renal masses demonstrated tumor signals. Tumor vascularity in malignant lesions gives rise to abnormal, high-velocity, Doppler-shifted signals that can help in the differential diagnosis of renal masses. 相似文献
19.
A comprehensive anatomic and radiographic analysis of the peribursal fat plane in 12 cadavers confirmed that the fat plane seen on radiographs represents extrasynovial fat lining the subacromial bursa and documented the anatomic relations of the bursa. A three-part retrospective clinical evaluation of rotator cuff tears, calcific tendinitis, and rheumatoid arthritis was performed. Two osteoradiologists blindly graded the appearance of the peribursal fat plane with the shoulder in external versus internal rotation in 21 patients with arthrographically intact rotator cuffs and 21 patients with disrupted rotator cuffs. The peribursal fat plane was seen better with disrupted rotator cuffs. The peribursal fat plane was seen better with the shoulder in internal rotation and was seen in 60% of control subjects but only 21% of patients with rotator cuff tears. Partial or complete obliteration of this fat plane is a sensitive (79%) but less specific (60%) indicator of rotator cuff tears. Obliteration of the peribursal fat plane by inflammatory processes in adjacent tissues, including calcific tendinitis and rheumatoid arthritis, occurred with a high frequency. 相似文献
20.